1. Field of the Invention
The instant invention relates in general to an improvement in tire structure and method of programmed transmission of power through tires to, in such a manner, improve the interface of the tire with a supporting surface. More particularly, the instant invention pertains to the programmed transmission of torque from an inner annular member to an outer annular member to provide a favorable force couple between the contact of the tire tread on a supporting surface and an off vertical center location on the outer annular member to which the torque is applied.
2. Description of the Prior Art
Tire constructure, and materials for constructing tires, is a rather well-defined field. Classically, tires have been constructed of bias cord plies which join the tire bead at opposed angles between a normal direction to the bead to a tangential direction to the bead. The bias cord plies overlap in opposite directions and are cured with a rubber matrix to form a unitary, flexible structure. Cords may be constructed of, for instance, polymers, copolymers, fiber glass, steel or other such materials. The cords are pliable and extremely strong with regard to tensile strength. Thus, the cords lend strength to the tire construction and the binding rubber provides air impermeability and, in the tread area, traction and flexibility. A gas under pressure is contained within the tire carcass to prestress the cord areas of the tire thereby permitting the flexible tire structure to support substantial weight.
A more recent improvement is the bias-belted tire in which a tire constructed in the conventional bias ply fashion incorporates one or more belts under the tread area. As can be readily apreciated, the bias ply tires, with the cord plies running at opposed angles, tend to distort as the tire rolls and is deformed at the contact area. This imparts a scrubbing action to the tread area being distorted at the contact area of the ground and, accordingly, increases tire temperature and tire wear while compromising energy consumption and traction. In the bias-belted tire, the belts serve to minimize the scrubbing in the tread area by stabilizing the dimensions of the contact patch.
In perhaps the ultimate currently available tire, one or more plies of cord running in directions normal to the bear are utilized in conjunction with a belted annular area under the tread. This radial tire construction not only provides the stabilizing influence of the belt under the tread, but also provides a cord construction which readily deflects in the sidewall portion to accommodate deformation of the tire at the contact patch. By accommodating this deformation in the more flexible sidewalls, a particularly stable tread area can be provided.
In all of the above-mentioned constructions, torque is transmitted from the rim to the tread area through the unitary flexible sidewall construction. Thus, torque transmission is in the manner of the traditional wheel and axle in which a torque moment from the center of rotation to the periphery of the outer surface of the tire exists. The weight component is transmitted radially between the center of rotation and, on the average, the center of the contact patch in a vertical fashion. Thus, whatever the construction or material in the above-discussed conventional tire designs, torque and weight are both transmitted essentially through a vertical diameter from the bottom of the wheel, or other contact point of the wheel with the supporting surface, and the center of the wheel.